JPH0289010A - coated optical fiber - Google Patents

Abstract

PURPOSE:To improve alkali resistance and acid resistance by using a glass resin compd. as the polyol component to be compounded with a (meth)acryl oligomer. CONSTITUTION:An energy ray curing type resin is applied on the outer periphery of an optical fiber 1 and is cured by irradiation of energy rays to form a coating layer 2. The energy ray curing type resin contains an acryl or methacryl oligomer, a reaction diluent and a polymn. initiator as its essential components. The polyol component to be compounded with the acryl or methacryl oligomer is a glass resin compd. This glass resin has a so-called ladder structure and is extremely low in alkali solubility and acid solubility. The alkali resistance and acid resistance of the coating are improved in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Denominator> The present invention relates to a coated optical fiber in which a coating layer cured by energy rays such as ultraviolet rays is formed on the outer periphery of the optical fiber.

<Prior Art> In optical fibers used for optical communications, it is considered preferable to immediately apply a plastic coating to the outer periphery of any optical fiber, not only optical glass fiber or quartz-based glass fiber, after being made into a fiber. This is to prevent the strength of the fiber from deteriorating due to scratches on the surface of the fiber that occur when the fiber is made into a fiber, or cracks that grow when the bare fiber is exposed to the air. In addition to thermosetting silicone resins, energy ray curable resins such as ultraviolet ray curable resins (hereinafter referred to as "UV resins") and radiation curable resins are generally used for such plastic layers. In particular, demand for UV resin-coated optical fibers is increasing.

Such UV@grease-coated optical fibers can be produced, for example, by continuously applying UV resin using a coating die to an optical fiber drawn in a drawing furnace, and then curing the applied UV resin by irradiating ultraviolet rays. Manufactured. Furthermore, such UV resin-coated optical fibers are further coated with a secondary coating either singly or in combination to form optical fiber cores.

<Problems to be Solved by the Invention> Examples of UV resins used for the above-mentioned primary coating include epoxy acrylate, urethane acrylate, and polyester acrylate, but these resins have the drawback of being extremely sensitive to acids and alkalis. are doing.

For example, 80℃, PH13 Na0HWI solution or 80℃
, PHI in HCI solution for 1 day f! & If soaked, it will decompose.

The outer sheath of general optical cables can become punctured due to unforeseen accidents, and acidic or alkaline water collected in manholes can infiltrate into the cable. Although this method can be applied to cables that have measures taken to prevent water from entering, it cannot be applied to ordinary cables.

In view of these circumstances, the present invention aims to provide a coated optical fiber whose coating has acid resistance and alkali resistance.

<II! Means for Solving the Problem> A coated optical fiber according to the present invention that achieves the above object,
Apply energy ray-curable resin to the outer circumference of the optical fiber,
A coated optical fiber formed by applying a coating layer by curing by irradiation with energy rays, comprising an acrylic or methacrylic oligomer consisting of an acrylate or methacrylate component, an isocyanate component, and a polyol component, a reactive diluent, and a polymerization initiator. , and is characterized in that the polyol component uses an energy ray curable resin that is a glass resin compound.

As mentioned above, the energy ray-curable resin used in the present invention has an acrylic or methacrylic oligomer, a reactive diluent, and a polymerization initiator as essential components, and if necessary, an acrylic resin, polyamide resin,
Various modifying resins such as polyether resins, polyurethane resins, polyamideimide resins, silicone resins, and phenol resins, and various additives such as organosilicon compounds and surfactants may be blended. In addition, from the viewpoint of workability, the viscosity of the energy ray-curable resin is usually 10 at 25°C.
It is preferable that mn is in the range of 00 to 10,000 centivoise.

The acrylic or methacrylic oligomer (hereinafter, acrylic or methacrylic oligomer is referred to as (meth)acrylic oligomer) used in the present invention refers to an acrylate or methacrylate component (hereinafter, acrylate or methacrylate is referred to as (meth)acrylate), It consists of an isocyanate component and a polyol component.

Here, as the (meth)acrylate component, those having a hydroxyalkyl group having about 2 to 4 carbon atoms, such as 2-human tetraxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate, are used.

Examples of the isocyanate component include tolylene diisocyanate, diphenylmethane diisocyanate, p-phenylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and isophorone diisocyanate.

The glass resin used in the present invention is represented by the general formula: Such glass resin has a so-called ladder structure and has extremely low alkali solubility and acid solubility. Therefore, the alkali resistance and #4 acidity of the coating can be improved. It was also experimentally confirmed that heat resistance was improved.

The (meth)acrylic oligomer used in such a glass resin is preferably used in an amount of 10 to 90% by weight in the energy ray curable resin.

This is because when the amount of fi is less than 10% by weight, the glass resin content is small, so the effect of improving Ni alkalinity and acid resistance is not noticeable.On the other hand, when it exceeds 90% by weight, the viscosity of the entire resin increases, and the workability and application This is because the properties are markedly reduced and both are unfavorable.

The following can be mentioned as the above-mentioned reactive diluent.

2-Ethylhexyl (meth)acrylate, (meth)acrylate of tetrahydrofurfuryl alcohol caprolactone adduct, (meth)acrylate of nonylphenol ethylene oxide adduct, polyethylene glycol di(methane 7-acrylate), polypropylene glycol di(meth)acrylate, Pisfu nordiethylene glycol di(meth)acrylate, hydrogenated bisphenol triethylene glycol di(meth)acrylate
Mono- or poly(meth)acrylates such as acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and epoxy(meth)acrylate synthesized from bisphenol diglycidyl ether.

Furthermore, the following vinyl compounds can also be used as the reactive diluent.

diallyl adipate, diallyl phthalate, triallyl trimellitate, Allyl esters such as triallylisocyanure-1, styrene, vinyl acetate, N-vinylpyrrolidone, N,N-dimethylacrylamide, N,N-dimethylaminopropylacrylamide, N,N-dimethylaminoethyl acrylate.

The polymerization initiator used in the present invention is preferably one that can quickly cure the resin composition by irradiation with energy rays, and is particularly suitable for use as an initiator and sensitizer in conventional ultraviolet curable paints. The one you have is suitable. Some examples are shown below.

benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-methylbenzoin, benzophenone, michler's ketone, benzil, benzyl dimethyl ketal, benzyl diethyl ketal, anthraquinone, methylanthraquinone, 2.2-jethoxyacetophenone, 2-methylthioxanthone, 2-isopropylthioxanthone, 2-ri a lothioxanthone, anthracene, 1.1-dichloroacetophenone, Methyl orthobenzoylbenzoate.

Furthermore, as the polymerization initiator, a small amount of sensitizing aid such as amines may be used together with these initiators.

The amount of polymerization initiator added is usually 1 part per 100 parts by weight of the (meth)acrylic oligomer and the reactive diluent.
About 10 parts by weight, preferably 1 to 5 parts by weight may be used.

If the amount of this polymerization initiator is too small, it will be difficult to satisfy the curability, while if it exceeds the predetermined value, no further improvement in the curing rate can be expected.

Examples> Preferred examples of the present invention and comparative examples for comparison will be described below.

Example 1 1 mole of glass resin with an average molecular weight of 2000 (one in which R is a methyl group in the above general formula (1)) and 4 moles of tolylene diisocyanate were charged into a 51-sized four-bottle flask equipped with a stirrer, a condenser, and a thermometer. , and reacted at 60 to 70°C for 2 hours. Then, 2-hydroxyethyl acrylate 4
mol was added, and the reaction was continued until the characteristic absorption band at 2270 cm-' of the isocyanate group disappeared according to an infrared absorption spectrum.

1.40 parts of 2-ethylhexyl acrylate as a reactive diluent and 3 parts of benzoin methyl ether as a polymerization initiator were blended into 60 parts of the urethane acrylate oligomer thus obtained (indicates the mlfi part, the same applies hereinafter). An energy ray-curable resin was obtained.

By applying this energy ray curable resin around the optical fiber obtained by drawing and irradiating it with ultraviolet rays, the first
As shown in the figure, a coated optical fiber 3 was obtained by forming a coating layer 2 around an optical fiber 1.

A 1m coated optical fiber 3 with a length of 50+++m and a diameter of 3f
Wrap around flI11 mandrel, 80℃, PH1
The alkali resistance and acid resistance were tested by immersing them in a NaOH aqueous solution of No. 3 and an HCI aqueous solution of PHI at 80° C., respectively.

The time it took for the coated optical fiber 3 to break was 8 days and 10 days, respectively, and it was recognized that the alkali resistance and acid resistance of the coating were poor.

Example 2 An unobtainable urethane acrylate oligomer was obtained in the same manner as in Example 1, except that a glass resin of general formula (1) in which R was an ethyl group was used as the glass resin. 40 parts of 2-ethylhexyl acrylate as a reactive diluent and 3 parts of benzoin methyl ether as a polymerization initiator were blended with 60 parts of this urethane acrylate oligomer to obtain an energy ray curable resin.

A coated optical fiber 3 was manufactured in the same manner as in Example 1 using this energy ray curable resin.

When this coated optical fiber 3 was similarly tested,
The time required for rupture in alkali and acid was 8 days and 11 days, respectively.

Example 3 A urethane acrylate oligomer was obtained in the same manner as in Example 1 except that a glass resin in which R in the general formula (1) was a phenyl group was used as the glass resin. 40 parts of 2-ethylhexyl acrylate as a reactive diluent and 3 parts of benzoin methyl ether as a polymerization initiator were blended with 60 parts of this urethane oligomer to obtain an energy ray curable resin.

Using this energy ray curing resin, a coated optical fiber 3 was prepared in the same manner as in Example 1.

When this coated optical fiber 3 was similarly tested,
The time to rupture in alkali and acid is 10 respectively.
It was 13 days.

Comparative Example 1 95 parts of 2-ethylhexyl acrylate as a reactive diluent and 3 parts of benzoin methyl ether as a polymerization initiator were blended with 5 parts of urethane acrylate oligomer obtained in the same manner as in Example 1 to produce an energy ray-curable type. Resin was obtained.

A coated optical fiber 3 was manufactured in the same manner as in Example 1 using this energy ray curable resin.

When this coated optical fiber 3 was tested in the same manner as in Example 1, it took 24 hours and 36 hours to break in alkali and acid, respectively.

Comparative Example 2 Same as Example 1 fJ)? An energy beam curable resin was obtained by blending 95 parts of urethane acrylate oligomer with 5 parts of 2-ethylhexyl acrylate as a reactive diluent and 3 parts of benzoin methyl ether as a polymerization initiator.

Using this energy ray curable resin, a coated optical fiber 3 was manufactured in the same manner as in Example 1.

This coated optical fiber 3 had a very high viscosity of 11,000 centivoise at 25° C. of the energy ray curable resin, so its appearance and shape were severely damaged.

Comparative Example 3 A urethane acrylate oligomer was obtained in the same manner as in Example 1 except that polyoxytetramethylene glycol having an average molecular weight of 2000 was used instead of the glass resin.

To 60 parts of this urethane acrylate oligomer, 40 parts of 2-ethylhexyl acrylate as a reactive diluent,
3 parts of benzoin methyl ether was blended as a polymerization initiator to obtain an energy ray curable resin.

A coated optical fiber in which a coating layer was formed around the optical fiber was manufactured in the same manner as in Example 1 using this energy ray curable resin.

When this coated optical fiber 3 was tested in the same manner as in Example 1, the time taken to break in alkali and acid was as follows:
20 hours each.

It took 30 hours◎ <Effects of the invention>That's all 5! As explained above, in the present invention, since a glass resin compound is used as the polyol component blended into the (meth)acrylic oligomer of the +f1 energy ray curable resin, it has alkali resistance and acid resistance, as well as improved heat resistance. We can provide coated optical fibers with

[Brief explanation of drawings]

FIG. 1 is a sectional view of a coated optical fiber according to an embodiment of the present invention. In the drawings, 1 is an optical fiber, 2 is a coating M1, and 3 is a coated optical fiber.

Claims (3)

[Claims] (1) In a coated optical fiber in which an energy ray-curable resin is applied to the outer periphery of the optical fiber and cured by energy ray irradiation to form a coating layer, an acrylic or methacrylate component, an isocyanate component, and a polyol component are used. A coated optical fiber characterized in that it uses an energy ray-curable resin that has a methacrylic oligomer, a reactive diluent, and a polymerization initiator, and in which the polyol component is a glass resin compound. (2) The glass resin compound has the following general formula, ▲mathematical formula, chemical formula, table, etc.▼ (However, R is an alkyl group such as a methyl group or an ethyl group, or an aryl group such as a phenyl group, and n represents a repeating unit. .) The coated optical fiber according to claim 1. (3) The coated optical fiber according to claim 1 or 2, wherein the energy beam curable resin contains 10 to 90% by weight of acrylic or methacrylic oligomer.